基本情報

所属

• 電子科学研究所　生命科学研究部門

職名

• 教授

学位

• 博士(理学)（2006年03月 東京大学）

J-Global ID

• 201701001801587230

プロフィール

• 2006年 東京大学大学院 理学系研究科 物理学専攻 博士課程修了後、（株）日立製作所 研究員（途中、カリフォルニア大学アーバイン校 客員研究員を兼任、2012年11月-2013年11月）、東京大学大学院理学系研究科化学専攻 助教を経て2020年6月より北海道大学 電子科学研究所 教授。2017年-2021年 JSTさきがけ研究者(兼任)。2022年よりJST CREST研究代表者。専門は光物理、光応用工学全般。これまでに量子光学・量子情報科学、光ディスク・光通信技術、生体観察向け非線形光学顕微鏡（二光子、SHG、CARS）、高速蛍光顕微鏡の研究を行ってきた。光科学、情報科学、生命科学の融合領域の開拓を目標に掲げて研究を行っている。

  
  
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研究分野

• ライフサイエンス / 生物物理学 / バイオイメージング
• ナノテク・材料 / 光工学、光量子科学

担当教育組織

•  修士課程　情報科学院
•  博士課程　情報科学院

職歴

• 2020年06月 - 現在 北海道大学 電子科学研究所 教授
• 2014年12月 - 2020年05月 東京大学 大学院理学系研究科 助教
• 2006年04月 - 2014年11月 ㈱日立製作所 中央研究所
• 2012年11月 - 2013年11月 University of California, Irvine Department of Chemistry Assistant Specialist

学歴

• 2002年04月 - 2006年03月   東京大学   大学院理学系研究科   物理学専攻
• 1998年04月 - 2002年03月   東京大学   理学部   物理学科

研究活動情報

論文

• Large-volume focus control at 10 MHz refresh rate via fast line-scanning amplitude-encoded scattering-assisted holography

  Atsushi Shibukawa, Ryota Higuchi, Gookho Song, Hideharu Mikami, Yuki Sudo, Mooseok Jang

  Nature Communications 15 1 2024年04月08日 

  Abstract The capability of focus control has been central to optical technologies that require both high temporal and spatial resolutions. However, existing varifocal lens schemes are commonly limited to the response time on the microsecond timescale and share the fundamental trade-off between the response time and the tuning power. Here, we propose an ultrafast holographic focusing method enabled by translating the speed of a fast 1D beam scanner into the speed of the complex wavefront modulation of a relatively slow 2D spatial light modulator. Using a pair of a digital micromirror device and a resonant scanner, we demonstrate an unprecedented refresh rate of focus control of 31 MHz, which is more than 1,000 times faster than the switching rate of a digital micromirror device. We also show that multiple micrometer-sized focal spots can be independently addressed in a range of over 1 MHz within a large volume of 5 mm × 5 mm × 5.5 mm, validating the superior spatiotemporal characteristics of the proposed technique – high temporal and spatial precision, high tuning power, and random accessibility in a three-dimensional space. The demonstrated scheme offers a new route towards three-dimensional light manipulation in the 100 MHz regime.
• Virtual-freezing fluorescence imaging flow cytometry with 5-aminolevulinic acid stimulation and antibody labeling for detecting all forms of circulating tumor cells.

  Hiroki Matsumura, Larina Tzu-Wei Shen, Akihiro Isozaki, Hideharu Mikami, Dan Yuan, Taichi Miura, Yuto Kondo, Tomoko Mori, Yoshika Kusumoto, Masako Nishikawa, Atsushi Yasumoto, Aya Ueda, Hiroko Bando, Hisato Hara, Yuhong Liu, Yunjie Deng, Masahiro Sonoshita, Yutaka Yatomi, Keisuke Goda, Satoshi Matsusaka

  Lab on a chip 23 6 1561 - 1575 2023年03月14日 

  Circulating tumor cells (CTCs) are precursors to cancer metastasis. In blood circulation, they take various forms such as single CTCs, CTC clusters, and CTC-leukocyte clusters, all of which have unique characteristics in terms of physiological function and have been a subject of extensive research in the last several years. Unfortunately, conventional methods are limited in accurately analysing the highly heterogeneous nature of CTCs. Here we present an effective strategy for simultaneously analysing all forms of CTCs in blood by virtual-freezing fluorescence imaging (VIFFI) flow cytometry with 5-aminolevulinic acid (5-ALA) stimulation and antibody labeling. VIFFI is an optomechanical imaging method that virtually freezes the motion of fast-flowing cells on an image sensor to enable high-throughput yet sensitive imaging of every single event. 5-ALA stimulates cancer cells to induce the accumulation of protoporphyrin (PpIX), a red fluorescent substance, making it possible to detect all cancer cells even if they show no expression of the epithelial cell adhesion molecule, a typical CTC biomarker. Although PpIX signals are generally weak, VIFFI flow cytometry can detect them by virtue of its high sensitivity. As a proof-of-principle demonstration of the strategy, we applied cancer cells spiked in blood to the strategy to demonstrate image-based detection and accurate classification of single cancer cells, clusters of cancer cells, and clusters of a cancer cell(s) and a leukocyte(s). To show the clinical utility of our method, we used it to evaluate blood samples of four breast cancer patients and four healthy donors and identified EpCAM-positive PpIX-positive cells in one of the patient samples. Our work paves the way toward the determination of cancer prognosis, the guidance and monitoring of treatment, and the design of antitumor strategies for cancer patients.
• Deep imaging flow cytometry.

  Kangrui Huang, Hiroki Matsumura, Yaqi Zhao, Maik Herbig, Dan Yuan, Yohei Mineharu, Jeffrey Harmon, Justin Findinier, Mai Yamagishi, Shinsuke Ohnuki, Nao Nitta, Arthur R Grossman, Yoshikazu Ohya, Hideharu Mikami, Akihiro Isozaki, Keisuke Goda

  Lab on a chip 22 5 876 - 889 2022年03月01日 

  Imaging flow cytometry (IFC) has become a powerful tool for diverse biomedical applications by virtue of its ability to image single cells in a high-throughput manner. However, there remains a challenge posed by the fundamental trade-off between throughput, sensitivity, and spatial resolution. Here we present deep-learning-enhanced imaging flow cytometry (dIFC) that circumvents this trade-off by implementing an image restoration algorithm on a virtual-freezing fluorescence imaging (VIFFI) flow cytometry platform, enabling higher throughput without sacrificing sensitivity and spatial resolution. A key component of dIFC is a high-resolution (HR) image generator that synthesizes "virtual" HR images from the corresponding low-resolution (LR) images acquired with a low-magnification lens (10×/0.4-NA). For IFC, a low-magnification lens is favorable because of reduced image blur of cells flowing at a higher speed, which allows higher throughput. We trained and developed the HR image generator with an architecture containing two generative adversarial networks (GANs). Furthermore, we developed dIFC as a method by combining the trained generator and IFC. We characterized dIFC using Chlamydomonas reinhardtii cell images, fluorescence in situ hybridization (FISH) images of Jurkat cells, and Saccharomyces cerevisiae (budding yeast) cell images, showing high similarities of dIFC images to images obtained with a high-magnification lens (40×/0.95-NA), at a high flow speed of 2 m s-1. We lastly employed dIFC to show enhancements in the accuracy of FISH-spot counting and neck-width measurement of budding yeast cells. These results pave the way for statistical analysis of cells with high-dimensional spatial information.
• AI on a chip.

  Akihiro Isozaki, Jeffrey Harmon, Yuqi Zhou, Shuai Li, Yuta Nakagawa, Mika Hayashi, Hideharu Mikami, Cheng Lei, Keisuke Goda

  Lab on a chip 20 17 3074 - 3090 2020年08月26日 

  Artificial intelligence (AI) has dramatically changed the landscape of science, industry, defence, and medicine in the last several years. Supported by considerably enhanced computational power and cloud storage, the field of AI has shifted from mostly theoretical studies in the discipline of computer science to diverse real-life applications such as drug design, material discovery, speech recognition, self-driving cars, advertising, finance, medical imaging, and astronomical observation, where AI-produced outcomes have been proven to be comparable or even superior to the performance of human experts. In these applications, what is essentially important for the development of AI is the data needed for machine learning. Despite its prominent importance, the very first process of the AI development, namely data collection and data preparation, is typically the most laborious task and is often a limiting factor of constructing functional AI algorithms. Lab-on-a-chip technology, in particular microfluidics, is a powerful platform for both the construction and implementation of AI in a large-scale, cost-effective, high-throughput, automated, and multiplexed manner, thereby overcoming the above bottleneck. On this platform, high-throughput imaging is a critical tool as it can generate high-content information (e.g., size, shape, structure, composition, interaction) of objects on a large scale. High-throughput imaging can also be paired with sorting and DNA/RNA sequencing to conduct a massive survey of phenotype-genotype relations whose data is too complex to analyze with traditional computational tools, but is analyzable with the power of AI. In addition to its function as a data provider, lab-on-a-chip technology can also be employed to implement the developed AI for accurate identification, characterization, classification, and prediction of objects in mixed, heterogeneous, or unknown samples. In this review article, motivated by the excellent synergy between AI and lab-on-a-chip technology, we outline fundamental elements, recent advances, future challenges, and emerging opportunities of AI with lab-on-a-chip technology or "AI on a chip" for short.
• Raman image-activated cell sorting.

  Nao Nitta, Takanori Iino, Akihiro Isozaki, Mai Yamagishi, Yasutaka Kitahama, Shinya Sakuma, Yuta Suzuki, Hiroshi Tezuka, Minoru Oikawa, Fumihito Arai, Takuya Asai, Dinghuan Deng, Hideya Fukuzawa, Misa Hase, Tomohisa Hasunuma, Takeshi Hayakawa, Kei Hiraki, Kotaro Hiramatsu, Yu Hoshino, Mary Inaba, Yuki Inoue, Takuro Ito, Masataka Kajikawa, Hiroshi Karakawa, Yusuke Kasai, Yuichi Kato, Hirofumi Kobayashi, Cheng Lei, Satoshi Matsusaka, Hideharu Mikami, Atsuhiro Nakagawa, Keiji Numata, Tadataka Ota, Takeichiro Sekiya, Kiyotaka Shiba, Yoshitaka Shirasaki, Nobutake Suzuki, Shunji Tanaka, Shunnosuke Ueno, Hiroshi Watarai, Takashi Yamano, Masayuki Yazawa, Yusuke Yonamine, Dino Di Carlo, Yoichiroh Hosokawa, Sotaro Uemura, Takeaki Sugimura, Yasuyuki Ozeki, Keisuke Goda

  Nature communications 11 1 3452 - 3452 2020年07月10日 

  The advent of image-activated cell sorting and imaging-based cell picking has advanced our knowledge and exploitation of biological systems in the last decade. Unfortunately, they generally rely on fluorescent labeling for cellular phenotyping, an indirect measure of the molecular landscape in the cell, which has critical limitations. Here we demonstrate Raman image-activated cell sorting by directly probing chemically specific intracellular molecular vibrations via ultrafast multicolor stimulated Raman scattering (SRS) microscopy for cellular phenotyping. Specifically, the technology enables real-time SRS-image-based sorting of single live cells with a throughput of up to ~100 events per second without the need for fluorescent labeling. To show the broad utility of the technology, we show its applicability to diverse cell types and sizes. The technology is highly versatile and holds promise for numerous applications that are previously difficult or undesirable with fluorescence-based technologies.
• Sequentially addressable dielectrophoretic array for high-throughput sorting of large-volume biological compartments.

  A Isozaki, Y Nakagawa, M H Loo, Y Shibata, N Tanaka, D L Setyaningrum, J-W Park, Y Shirasaki, H Mikami, D Huang, H Tsoi, C T Riche, T Ota, H Miwa, Y Kanda, T Ito, K Yamada, O Iwata, K Suzuki, S Ohnuki, Y Ohya, Y Kato, T Hasunuma, S Matsusaka, M Yamagishi, M Yazawa, S Uemura, K Nagasawa, H Watarai, D Di Carlo, K Goda

  Science advances 6 22 eaba6712 - eaba6712 2020年05月 [査読有り][通常論文]
   

  Droplet microfluidics has become a powerful tool in precision medicine, green biotechnology, and cell therapy for single-cell analysis and selection by virtue of its ability to effectively confine cells. However, there remains a fundamental trade-off between droplet volume and sorting throughput, limiting the advantages of droplet microfluidics to small droplets (<10 pl) that are incompatible with long-term maintenance and growth of most cells. We present a sequentially addressable dielectrophoretic array (SADA) sorter to overcome this problem. The SADA sorter uses an on-chip array of electrodes activated and deactivated in a sequence synchronized to the speed and position of a passing target droplet to deliver an accumulated dielectrophoretic force and gently pull it in the direction of sorting in a high-speed flow. We use it to demonstrate large-droplet sorting with ~20-fold higher throughputs than conventional techniques and apply it to long-term single-cell analysis of Saccharomyces cerevisiae based on their growth rate.
• High-speed single-pixel imaging by frequency-time-division multiplexing.

  Hiroshi Kanno, Hideharu Mikami, Keisuke Goda

  Optics letters 45 8 2339 - 2342 2020年04月15日 

  We propose and experimentally demonstrate high-speed single-pixel imaging by integrating frequency-division multiplexing and time-division multiplexing (techniques used widely in telecommunications) and applying the combined technique, namely, frequency-time-division multiplexing (FTDM), to optical imaging. Specifically, FTDM single-pixel imaging uses an array of broadband, spatially distributed, dual-frequency combs (i.e., spatial dual combs) for multidimensional illumination and detects an image-encoded time-domain signal with a single-pixel photodetector in a FTDM manner. As a proof-of-principle demonstration, we use the method to show ultrafast two-color (bright-field and fluorescence) single-pixel microscopy of breast cancer cells at a high frame rate of 32,000 fps and ultrafast image velocimetry of fluorescent particles flowing at a high speed of ${ \gt },{2}\;{\rm m/s}$>2m/s.
• Virtual-freezing fluorescence imaging flow cytometry.

  Hideharu Mikami, Makoto Kawaguchi, Chun-Jung Huang, Hiroki Matsumura, Takeaki Sugimura, Kangrui Huang, Cheng Lei, Shunnosuke Ueno, Taichi Miura, Takuro Ito, Kazumichi Nagasawa, Takanori Maeno, Hiroshi Watarai, Mai Yamagishi, Sotaro Uemura, Shinsuke Ohnuki, Yoshikazu Ohya, Hiromi Kurokawa, Satoshi Matsusaka, Chia-Wei Sun, Yasuyuki Ozeki, Keisuke Goda

  Nature communications 11 1 1162 - 1162 2020年03月06日 [査読有り][通常論文]
   

  By virtue of the combined merits of flow cytometry and fluorescence microscopy, imaging flow cytometry (IFC) has become an established tool for cell analysis in diverse biomedical fields such as cancer biology, microbiology, immunology, hematology, and stem cell biology. However, the performance and utility of IFC are severely limited by the fundamental trade-off between throughput, sensitivity, and spatial resolution. Here we present an optomechanical imaging method that overcomes the trade-off by virtually freezing the motion of flowing cells on the image sensor to effectively achieve 1000 times longer exposure time for microscopy-grade fluorescence image acquisition. Consequently, it enables high-throughput IFC of single cells at >10,000 cells s-1 without sacrificing sensitivity and spatial resolution. The availability of numerous information-rich fluorescence cell images allows high-dimensional statistical analysis and accurate classification with deep learning, as evidenced by our demonstration of unique applications in hematology and microbiology.
• Accurate classification of microalgae by intelligent frequency-division-multiplexed fluorescence imaging flow cytometry

  Jeffrey Harmon, Hideharu Mikami, Hiroshi Kanno, Takuro Ito, Keisuke Goda

  OSA CONTINUUM 3 3 430 - 440 2020年03月 

  Microalgae have recently been gaining attention for their versatile uses and environmentally friendly benefits. Accurate characterization and classification of a large population of microalgal cells with single-cell resolution are highly valuable for their diverse applications such as water treatment, biofuel production, food, and nitrogen-fixing biofertilization. Here we demonstrate accurate classification of spherical microalgal species using recently developed frequency-division-multiplexed fluorescence imaging flow cytometry and machine learning. We obtained three-color (bright-field and two-color fluorescence) images of microalgal cells, quantified morphological features of the cells using the images, and classified six microalgae using features via a support vector machine. By virtue of the rich information content of the three-color images of microalgal cells, we classified six microalgae with a high accuracy of 99.8%. Our method can evaluate large populations of microalgal cells with single-cell resolution and hence holds promise for various applications such as environmental monitoring of the hydrosphere. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
• Intelligent image-activated cell sorting 2.0

  Akihiro Isozaki, Hideharu Mikami, Hiroshi Tezuka, Hiroki Matsumura, Kangrui Huang, Marino Akamine, Kotaro Hiramatsu, Takanori Iino, Takuro Ito, Hiroshi Karakawa, Yusuke Kasai, Yan Li, Yuta Nakagawa, Shinsuke Ohnuki, Tadataka Ota, Yong Qian, Shinya Sakuma, Takeichiro Sekiya, Yoshitaka Shirasaki, Nobutake Suzuki, Ehsen Tayyabi, Tsubasa Wakamiya, Muzhen Xu, Mai Yamagishi, Haochen Yan, Qiang Yu, Sheng Yan, Dan Yuan, Wei Zhang, Yaqi Zhao, Fumihito Arai, Robert E. Campbell, Christophe Danelon, Dino Di Carlo, Kei Hiraki, Yu Hoshino, Yoichiroh Hosokawa, Mary Inaba, Atsuhiro Nakagawa, Yoshikazu Ohya, Minoru Oikawa, Sotaro Uemura, Yasuyuki Ozeki, Takeaki Sugimura, Nao Nitta, Keisuke Goda

  Lab on a Chip 20 13 2263 - 2273 2020年 [査読有り][通常論文]
   

  The upgraded version of intelligent image-activated cell sorting (iIACS) has enabled higher-throughput and more sensitive intelligent image-based sorting of single live cells from heterogeneous populations.

• Author Correction: A practical guide to intelligent image-activated cell sorting.

  Akihiro Isozaki, Hideharu Mikami, Kotaro Hiramatsu, Shinya Sakuma, Yusuke Kasai, Takanori Iino, Takashi Yamano, Atsushi Yasumoto, Yusuke Oguchi, Nobutake Suzuki, Yoshitaka Shirasaki, Taichiro Endo, Takuro Ito, Kei Hiraki, Makoto Yamada, Satoshi Matsusaka, Takeshi Hayakawa, Hideya Fukuzawa, Yutaka Yatomi, Fumihito Arai, Dino Di Carlo, Atsuhiro Nakagawa, Yu Hoshino, Yoichiroh Hosokawa, Sotaro Uemura, Takeaki Sugimura, Yasuyuki Ozeki, Nao Nitta, Keisuke Goda

  Nature protocols 14 11 3273 - 3273 2019年11月 [査読有り][通常論文]
   

  An amendment to this paper has been published and can be accessed via a link at the top of the paper.
• A practical guide to intelligent image-activated cell sorting.

  Akihiro Isozaki, Hideharu Mikami, Kotaro Hiramatsu, Shinya Sakuma, Yusuke Kasai, Takanori Iino, Takashi Yamano, Atsushi Yasumoto, Yusuke Oguchi, Nobutake Suzuki, Yoshitaka Shirasaki, Taichiro Endo, Takuro Ito, Kei Hiraki, Makoto Yamada, Satoshi Matsusaka, Takeshi Hayakawa, Hideya Fukuzawa, Yutaka Yatomi, Fumihito Arai, Dino Di Carlo, Atsuhiro Nakagawa, Yu Hoshino, Yoichiroh Hosokawa, Sotaro Uemura, Takeaki Sugimura, Yasuyuki Ozeki, Nao Nitta, Keisuke Goda

  Nature protocols 14 8 2370 - 2415 2019年08月 [査読有り][通常論文]
   

  Intelligent image-activated cell sorting (iIACS) is a machine-intelligence technology that performs real-time intelligent image-based sorting of single cells with high throughput. iIACS extends beyond the capabilities of fluorescence-activated cell sorting (FACS) from fluorescence intensity profiles of cells to multidimensional images, thereby enabling high-content sorting of cells or cell clusters with unique spatial chemical and morphological traits. Therefore, iIACS serves as an integral part of holistic single-cell analysis by enabling direct links between population-level analysis (flow cytometry), cell-level analysis (microscopy), and gene-level analysis (sequencing). Specifically, iIACS is based on a seamless integration of high-throughput cell microscopy (e.g., multicolor fluorescence imaging, bright-field imaging), cell focusing, cell sorting, and deep learning on a hybrid software-hardware data management infrastructure, enabling real-time automated operation for data acquisition, data processing, intelligent decision making, and actuation. Here, we provide a practical guide to iIACS that describes how to design, build, characterize, and use an iIACS machine. The guide includes the consideration of several important design parameters, such as throughput, sensitivity, dynamic range, image quality, sort purity, and sort yield; the development and integration of optical, microfluidic, electrical, computational, and mechanical components; and the characterization and practical usage of the integrated system. Assuming that all components are readily available, a team of several researchers experienced in optics, electronics, digital signal processing, microfluidics, mechatronics, and flow cytometry can complete this protocol in ~3 months.
• Simple, stable, compact implementation of frequency-division-multiplexed microscopy by inline interferometry

  Hiroshi Kanno, Hideharu Mikami, Yasin Kaya, Yasuyuki Ozeki, Keisuke Goda

  Optics Letters 44 3 467 - 470 2019年 [査読有り][通常論文]
  
• High-Speed Imaging Meets Single-Cell Analysis

  Hideharu Mikami, Cheng Lei, Nao Nitta, Takeaki Sugimura, Takuro Ito, Yasuyuki Ozeki, Keisuke Goda

  CHEM 4 10 2278 - 2300 2018年10月 

  High-speed imaging is an indispensable tool in today's scientific research, industry, and energy because it enables blur-free observation and monitoring of fast transient dynamics. It is commonly used for various applications, including sports, manufacturing, and fusion science, in which slow-motion analysis is conducted to elucidate their dynamics. On the other hand, the past several years have seen another and radically new application of high-speed imaging, namely single-cell analysis-the study of individual biological cells among populations for identifying cell-to-cell differences and elucidating cellular heterogeneity invisible to population-averaged measurements. This exciting application has been made possible by exploiting high-speed imaging's capability of acquiring information-rich images at high frame rates to provide a snapshot library of numerous cells in a short duration of time (with one cell per frame). In this article, we review the principles of several unique high-speed imaging methods for microscopy and their emerging application to large-scale single-cell analysis.
• Intelligent Image-Activated Cell Sorting.

  Nao Nitta, Takeaki Sugimura, Akihiro Isozaki, Hideharu Mikami, Kei Hiraki, Shinya Sakuma, Takanori Iino, Fumihito Arai, Taichiro Endo, Yasuhiro Fujiwaki, Hideya Fukuzawa, Misa Hase, Takeshi Hayakawa, Kotaro Hiramatsu, Yu Hoshino, Mary Inaba, Takuro Ito, Hiroshi Karakawa, Yusuke Kasai, Kenichi Koizumi, SangWook Lee, Cheng Lei, Ming Li, Takanori Maeno, Satoshi Matsusaka, Daichi Murakami, Atsuhiro Nakagawa, Yusuke Oguchi, Minoru Oikawa, Tadataka Ota, Kiyotaka Shiba, Hirofumi Shintaku, Yoshitaka Shirasaki, Kanako Suga, Yuta Suzuki, Nobutake Suzuki, Yo Tanaka, Hiroshi Tezuka, Chihana Toyokawa, Yaxiaer Yalikun, Makoto Yamada, Mai Yamagishi, Takashi Yamano, Atsushi Yasumoto, Yutaka Yatomi, Masayuki Yazawa, Dino Di Carlo, Yoichiroh Hosokawa, Sotaro Uemura, Yasuyuki Ozeki, Keisuke Goda

  Cell 175 1 266 - 276 2018年09月20日 [査読有り][通常論文]
   

  A fundamental challenge of biology is to understand the vast heterogeneity of cells, particularly how cellular composition, structure, and morphology are linked to cellular physiology. Unfortunately, conventional technologies are limited in uncovering these relations. We present a machine-intelligence technology based on a radically different architecture that realizes real-time image-based intelligent cell sorting at an unprecedented rate. This technology, which we refer to as intelligent image-activated cell sorting, integrates high-throughput cell microscopy, focusing, and sorting on a hybrid software-hardware data-management infrastructure, enabling real-time automated operation for data acquisition, data processing, decision-making, and actuation. We use it to demonstrate real-time sorting of microalgal and blood cells based on intracellular protein localization and cell-cell interaction from large heterogeneous populations for studying photosynthesis and atherothrombosis, respectively. The technology is highly versatile and expected to enable machine-based scientific discovery in biological, pharmaceutical, and medical sciences.
• High-throughput imaging flow cytometry by optofluidic time-stretch microscopy

  Lei Cheng, Kobayashi Hirofumi, Wu Yi, Li Ming, Isozaki Akihiro, Yasumoto Atsushi, Mikami Hideharu, Ito Takuro, Nitta Nao, Sugimura Takeaki, Yamada Makoto, Yatomi Yutaka, Di Carlo Dino, Ozeki Yasuyuki, Goda Keisuke

  NATURE PROTOCOLS 13 7 1603 - 1631 2018年07月 [査読有り][通常論文]
   

  The ability to rapidly assay morphological and intracellular molecular variations within large heterogeneous populations of cells is essential for understanding and exploiting cellular heterogeneity. Optofluidic time-stretch microscopy is a powerful method for meeting this goal, as it enables high-throughput imaging flow cytometry for large-scale single-cell analysis of various cell types ranging from human blood to algae, enabling a unique class of biological, medical, pharmaceutical, and green energy applications. Here, we describe how to perform high-throughput imaging flow cytometry by optofluidic time-stretch microscopy. Specifically, this protocol provides step-by-step instructions on how to build an optical time-stretch microscope and a cell-focusing microfluidic device for optofluidic time-stretch microscopy, use it for high-throughput single-cell image acquisition with sub-micrometer resolution at >10,000 cells per s, conduct image construction and enhancement, perform image analysis for large-scale single-cell analysis, and use computational tools such as compressive sensing and machine learning for handling the cellular 'big data'. Assuming all components are readily available, a research team of three to four members with an intermediate level of experience with optics, electronics, microfluidics, digital signal processing, and sample preparation can complete this protocol in a time frame of 1 month.
• On-chip light-sheet fluorescence imaging flow cytometry at a high flow speed of 1 m/s

  Miura Taichi, Mikami Hideharu, Isozaki Akihiro, Ito Takuro, Ozeki Yasuyuki, Goda Keisuke

  BIOMEDICAL OPTICS EXPRESS 9 7 3424 - 3433 2018年07月01日 [査読有り][通常論文]
   

  We present on-chip fluorescence imaging flow cytometry by light-sheet excitation on a mirror-embedded microfluidic chip. The method allows us to obtain microscopy-grade fluorescence images of cells flowing at a high speed of 1 m/s, which is comparable to the flow speed of conventional non-imaging flow cytometers. To implement the light-sheet excitation of flowing cells in a microchannel, we designed and fabricated a mirror-embedded PDMS-based microfluidic chip. To show its broad utility, we used the method to classify large populations of microalgal cells (Euglena gracilis) and human cancer cells (human adenocarcinoma cells). Our method holds promise for large-scale single-cell analysis. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
• Ultrafast confocal fluorescence microscopy beyond the fluorescence lifetime limit

  Hideharu Mikami, Jeffrey Harmon, Hirofumi Kobayashi, Syed Hamad, Yisen Wang, Osamu Iwata, Kengo Suzuki, Takuro Ito, Yuri Aisaka, Natsumaro Kutsuna, Kazumichi Nagasawa, Hiroshi Watarai, Yasuyuki Ozeki, Keisuke Goda

  Optica 5 2 117 - 126 2018年02月20日 [査読有り][通常論文]
   

  Laser-scanning confocal fluorescence microscopy is an indispensable tool for biomedical research by virtue of its high spatial resolution. Its temporal resolution is equally important, but is still inadequate for many applications. Here we present a confocal fluorescence microscope that, for the first time to our knowledge, surpasses the highest possible frame rate constrained only by the fluorescence lifetime of fluorophores (typically a few to several nanoseconds). This microscope is enabled by integrating a broadband, spatially distributed, dual-frequency comb or spatial dual-comb and quadrature amplitude modulation for optimizing spectral efficiency into frequency-division multiplexing with single-pixel photodetection for signal integration. Specifically, we demonstrate confocal fluorescence microscopy at a record high frame rate of 16,000 frames/s. To show its broad biomedical utility, we use the microscope to demonstrate 3D volumetric confocal fluorescence microscopy of cellular dynamics at 104 volumes/s and confocal fluorescence imaging flow cytometry of hematological and microalgal cells at up to 2 m/s.
• High-speed bioimaging with frequency-division-multiplexed fluorescence confocal microscopy

  Hideharu Mikami, Jeffrey Harmon, Yasuyuki Ozeki, Keisuke Goda

  Proceedings of SPIE - The International Society for Optical Engineering 10251 2017年 [査読有り][通常論文]
   

  We present methods of fluorescence confocal microscopy that enable unprecedentedly high frame rate of > 10,000 fps. The methods are based on a frequency-division multiplexing technique, which was originally developed in the field of communication engineering. Specifically, we achieved a broad bandwidth (∼400 MHz) of detection signals using a dual-AOD method and overcame limitations in frame rate, due to a scanning device, by using a multi-line focusing method, resulting in a significant increase in frame rate. The methods have potential biomedical applications such as observation of sub-millisecond dynamics in biological tissues, in-vivo three-dimensional imaging, and fluorescence imaging flow cytometry.
• Rapid mesoscale multiphoton microscopy of human skin

  Mihaela Balu, Hideharu Mikami, Jue Hou, Eric O. Potma, Bruce J. Tromberg

  BIOMEDICAL OPTICS EXPRESS 7 11 4375 - 4387 2016年11月 [査読有り][通常論文]
   

  We present a multiphoton microscope designed for mesoscale imaging of human skin. The system is based on two-photon excited fluorescence and second-harmonic generation, and images areas of similar to 0.8x0.8 mm(2) at speeds of 0.8 fps (800x800 pixels; 12 frame averages) for high signal-to-noise ratio, with lateral and axial resolutions of 0.5 mu m and 3.3 mu m, respectively. The main novelty of this instrument is the design of the scan head, which includes a fast galvanometric scanner, optimized relay optics, a beam expander and high NA objective lens. Computed aberrations in focus are below the Marechal criterion of 0.07. rms for diffraction-limited performance. We demonstrate the practical utility of this microscope by ex-vivo imaging of wide areas in normal human skin. (C) 2016 Optical Society of America
• Ultrafast optical imaging technology: principles and applications of emerging methods

  Hideharu Mikami, Liang Gao, Keisuke Goda

  NANOPHOTONICS 5 4 497 - 509 2016年10月 [査読有り][通常論文]
   

  High-speed optical imaging is an indispensable technology for blur-free observation of fast transient dynamics in virtually all areas including science, industry, defense, energy, and medicine. High temporal resolution is particularly important for microscopy as even a slow event appears to occur "fast" in a small field of view. Unfortunately, the shutter speed and frame rate of conventional cameras based on electronic image sensors are significantly constrained by their electrical operation and limited storage. Over the recent years, several unique and unconventional approaches to high-speed optical imaging have been reported to circumvent these technical challenges and achieve a frame rate and shutter speed far beyond what can be reached with the conventional image sensors. In this article, we review the concepts and principles of such ultrafast optical imaging methods, compare their advantages and disadvantages, and discuss an entirely new class of applications that are possible using them.
• Ultrafast optical imaging technology: Principles and applications of emerging methods

  Hideharu Mikami, Liang Gao, Keisuke Goda

  Nanophotonics 5 4 441 - 453 2016年09月01日 [査読有り][通常論文]
   

  High-speed optical imaging is an indispensable technology for blur-free observation of fast transient dynamics in virtually all areas including science, industry, defense, energy, and medicine. High temporal resolution is particularly important for microscopy as even a slow event appears to occur "fast" in a small field of view. Unfortunately, the shutter speed and frame rate of conventional cameras based on electronic image sensors are significantly constrained by their electrical operation and limited storage. Over the recent years, several unique and unconventional approaches to high-speed optical imaging have been reported to circumvent these technical challenges and achieve a frame rate and shutter speed far beyond what can be reached with the conventional image sensors. In this article, we review the concepts and principles of such ultrafast optical imaging methods, compare their advantages and disadvantages, and discuss an entirely new class of applications that are possible using them.
• Large field of view multiphoton microscopy of human skin

  Mihaela Balu, Hideharu Mikami, Jue Hou, Eric O. Potma, Bruce J. Tromberg

  Progress in Biomedical Optics and Imaging - Proceedings of SPIE 9712 2016年 [査読有り][通常論文]
   

  Clinical examination crucially relies on the ability to quickly examine large tissue areas and rapidly zoom in to regions of interest. Skin lesions often show irregularity in color and appearance in general, especially when they start to progress towards malignancy. Large field of view (FOV) and automatic translation of the imaging area are critical in the assessment of the entire lesion. Imaging of limited FOVs of the lesion can easily result in false negative diagnosis. We present a multiphoton microscope based on two-photon excited fluorescence and second-harmonic generation that images FOVs of about 0.8 mm2 (without stitching adjacent FOVs) at speeds of 10 frames/second (800 x 800 pixels) with lateral and axial resolutions of 0.5 μm and 2.5 μm, respectively. The main novelty of this instrument is the design of the scan head, which includes a fast galvanometric scanner, relay optics, a beam expander and a high NA objective lens. We optimized the system based on the Olympus 25x, 1.05NA water immersion lens, that features a long working distance of 1 mm. Proper tailoring of the beam expander, which consists of the scan and tube lens elements, enables scaling of the FOV. The design criteria include a flat wavefront of the beam, minimum field curvature, and suppressed spherical aberrations. All aberrations in focus are below the Marechal criterion of 0.07λ rms for diffraction-limited performance. We demonstrate the practical utility of this microscope by ex-vivo imaging of wide FOVs in normal human skin.
• Large field of view multiphoton microscopy of human skin

  Mihaela Balu, Hideharu Mikami, Jue Hou, Eric O. Potma, Bruce J. Tromberg

  MULTIPHOTON MICROSCOPY IN THE BIOMEDICAL SCIENCES XVI 9712 2016年 [査読有り][通常論文]
   

  Clinical examination crucially relies on the ability to quickly examine large tissue areas and rapidly zoom in to regions of interest. Skin lesions often show irregularity in color and appearance in general, especially when they start to progress towards malignancy. Large field of view (FOV) and automatic translation of the imaging area are critical in the assessment of the entire lesion. Imaging of limited FOVs of the lesion can easily result in false negative diagnosis. We present a multiphoton microscope based on two-photon excited fluorescence and second-harmonic generation that images FOVs of about 0.8 mm(2) (without stitching adjacent FOVs) at speeds of 10 frames/second (800 x 800 pixels) with lateral and axial resolutions of 0.5 mu m and 2.5 mu m, respectively. The main novelty of this instrument is the design of the scan head, which includes a fast galvanometric scanner, relay optics, a beam expander and a high NA objective lens. We optimized the system based on the Olympus 25x, 1.05NA water immersion lens, that features a long working distance of 1 mm. Proper tailoring of the beam expander, which consists of the scan and tube lens elements, enables scaling of the FOV. The design criteria include a flat wavefront of the beam, minimum field curvature, and suppressed spherical aberrations. All aberrations in focus are below the Marechal criterion of 0.07 lambda rms for diffraction-limited performance. We demonstrate the practical utility of this microscope by ex-vivo imaging of wide FOVs in normal human skin.
• Enhanced speed in fluorescence imaging using beat frequency multiplexing

  Hideharu Mikami, Hirofumi Kobayashi, Yisen Wang, Syed Hamad, Yasuyuki Ozeki, Keisuke Goda

  HIGH-SPEED BIOMEDICAL IMAGING AND SPECTROSCOPY: TOWARD BIG DATA INSTRUMENTATION AND MANAGEMENT 9720 2016年 [査読有り][通常論文]
   

  Fluorescence imaging using radiofrequency-tagged emission (FIRE) is an emerging technique that enables higher imaging speed (namely, temporal resolution) in fluorescence microscopy compared to conventional fluorescence imaging techniques such as confocal microscopy and wide-field microscopy. It works based on the principle that it uses multiple intensity-modulated fields in an interferometric setup as excitation fields and applies frequency-division multiplexing to fluorescence signals. Unfortunately, despite its high potential, FIRE has limited imaging speed due to two practical limitations: signal bandwidth and signal detection efficiency. The signal bandwidth is limited by that of an acousto-optic deflector (AOD) employed in the setup, which is typically 100-200 MHz for the spectral range of fluorescence excitation (400-600 nm). The signal detection efficiency is limited by poor spatial mode-matching between two interfering fields to produce a modulated excitation field. Here we present a method to overcome these limitations and thus to achieve higher imaging speed than the prior version of FIRE. Our method achieves an increase in signal bandwidth by a factor of two and nearly optimal mode matching, which enables the imaging speed limited by the lifetime of the target fluorophore rather than the imaging system itself. The higher bandwidth and better signal detection efficiency work synergistically because higher bandwidth requires higher signal levels to avoid the contribution of shot noise and amplifier noise to the fluorescence signal. Due to its unprecedentedly high-speed performance, our method has a wide variety of applications in cancer detection, drug discovery, and regenerative medicine.
• Ultrafast Confocal Fluorescence Microscopy by Frequency-Division-Multiplexed Multi-Line Focusing

  Hideharu Mikami, Hirofumi Kobayashi, Syed Hamad, Yasuyuki Ozeki, Keisuke Goda

  2016 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) 2016年 [査読有り][通常論文]
   

  We propose and demonstrate ultrafast fluorescence confocal microscopy at a record high frame rate of 32,000 fps. This is made possible by frequency-division multiplexing with multi-line focusing.
• Compact and fully collinear light source for broadband multiplex CARS microscopy covering the fingerprint region

  Hideharu Mikami, Manabu Shiozawa, Masataka Shirai, Koichi Watanabe

  OPTICS EXPRESS 23 13 17217 - 17222 2015年06月 [査読有り][通常論文]
   

  Compact and fully collinear light source for multiplex coherent anti-Stokes Raman scattering (CARS) microscopy was proposed and demonstrated. It consists of only a microchip laser, a short photonic crystal fiber, and a longpass filter. It offers performance of sensitivity, bandwidth, and spectral resolution suitable for biomedical applications, especially covering the entire fingerprint region (500-1800 cm(-1)). It can be readily implemented by a commercially available microchip laser and a photonic crystal fiber. It has great potential to expand the utility of CARS microscopy to a wide variety of fields such as endoscopy. (C) 2015 Optical Society of America
• Compact and fully collinear light source for broadband multiplex CARS microscopy covering the fingerprint region

  Hideharu Mikami, Manabu Shiozawa, Masataka Shirai, Koichi Watanabe

  OPTICS EXPRESS 23 13 17217 - 17222 2015年06月 [査読有り][通常論文]
   

  Compact and fully collinear light source for multiplex coherent anti-Stokes Raman scattering (CARS) microscopy was proposed and demonstrated. It consists of only a microchip laser, a short photonic crystal fiber, and a longpass filter. It offers performance of sensitivity, bandwidth, and spectral resolution suitable for biomedical applications, especially covering the entire fingerprint region (500-1800 cm(-1)). It can be readily implemented by a commercially available microchip laser and a photonic crystal fiber. It has great potential to expand the utility of CARS microscopy to a wide variety of fields such as endoscopy. (C) 2015 Optical Society of America
• Compact light source for ultrabroadband coherent anti-Stoke Raman scattering (CARS) microscopy

  Hideharu Mikami, Manabu Shiozawa, Masataka Shirai, Koichi Watanabe

  OPTICS EXPRESS 23 3 2872 - 2878 2015年02月 [査読有り][通常論文]
   

  A compact light source module for ultrabroadband coherent anti-Stoke Raman scattering (CARS) microscopy was developed. It mainly consists of a nanosecond microchip laser, a photonic crystal fiber for Stokes light generation, and a single mode polarization maintaining fiber for pump light propagation. It is alignment-free and relatively low-cost compared with previous light sources of CARS microscopy. By using an assembled module, we successfully observed an ultrabroadband CARS spectrum and a CARS image of a murine adipocyte. The module is expected to greatly spread the CARS microscopy to various fields by its extreme easiness to handle. (C) 2015 Optical Society of America
• Quantitative index of arbitrary molar concentration for coherent anti-Stoke Raman scattering (CARS) spectroscopy and microscopy

  Hideharu Mikami, Manabu Shiozawa, Masataka Shirai, Koichi Watanabe

  OPTICS EXPRESS 23 4 5300 - 5311 2015年02月 [査読有り][通常論文]
   

  We propose a simple quantitative index for coherent anti-Stoke Raman scattering (CARS) spectroscopy and microscopy. Unlike previous similar indices, it can be applied to samples with arbitrary molar concentration, and it is robust against environmental change. Concentrations of aqueous hydrogen peroxide solution and lipid concentration distribution in a live murine adipocyte were successfully quantified by the new index. The index can be obtained in a broad range of CARS setups and it is readily applicable to quantitative CARS microscopy for deep inspection of samples such as biological specimens. (C) 2015 Optical Society of America
• Compact light source for ultrabroadband coherent anti-Stoke Raman scattering (CARS) microscopy

  Hideharu Mikami, Manabu Shiozawa, Masataka Shirai, Koichi Watanabe

  OPTICS EXPRESS 23 3 2872 - 2878 2015年02月 [査読有り][通常論文]
   

  A compact light source module for ultrabroadband coherent anti-Stoke Raman scattering (CARS) microscopy was developed. It mainly consists of a nanosecond microchip laser, a photonic crystal fiber for Stokes light generation, and a single mode polarization maintaining fiber for pump light propagation. It is alignment-free and relatively low-cost compared with previous light sources of CARS microscopy. By using an assembled module, we successfully observed an ultrabroadband CARS spectrum and a CARS image of a murine adipocyte. The module is expected to greatly spread the CARS microscopy to various fields by its extreme easiness to handle. (C) 2015 Optical Society of America
• Quantitative index of arbitrary molar concentration for coherent anti-Stoke Raman scattering (CARS) spectroscopy and microscopy

  Hideharu Mikami, Manabu Shiozawa, Masataka Shirai, Koichi Watanabe

  OPTICS EXPRESS 23 4 5300 - 5311 2015年02月 [査読有り][通常論文]
   

  We propose a simple quantitative index for coherent anti-Stoke Raman scattering (CARS) spectroscopy and microscopy. Unlike previous similar indices, it can be applied to samples with arbitrary molar concentration, and it is robust against environmental change. Concentrations of aqueous hydrogen peroxide solution and lipid concentration distribution in a live murine adipocyte were successfully quantified by the new index. The index can be obtained in a broad range of CARS setups and it is readily applicable to quantitative CARS microscopy for deep inspection of samples such as biological specimens. (C) 2015 Optical Society of America
• Microholographic optical data storage with spatial mode multiplexing

  Hideharu Mikami, Koichi Watanabe

  Japanese Journal of Applied Physics 52 9 2013年09月 [査読有り][通常論文]
   

  Microholographic optical data storage is a promising candidate for next-generation optical disc systems because of its potential huge capacity. We proposed and demonstrated a new novel multiplexing technique for microholographic optical data storage using spatial modes of an optical beam to enhance data capacity. Numerical simulation was performed to validate the proposal and it was estimated that the net increase of data capacity by applying two- and four-mode multiplexing with Hermite-Gaussian modes was 1.3 and 1.7 times, respectively. A proof-of-principle experiment for two-mode multiplexing was performed by using spatial modes equivalent to Laguerre-Gaussian modes and it was demonstrated that signal output was selectively obtained by choosing an appropriate spatial mode for reference light of phase-diversity homodyne detection. Because the proposed technique can be applied in conjunction with other multiplexing and multilevel techniques, it is expected to greatly increase the possible applications of future optical disc systems. © 2013 The Japan Society of Applied Physics.
• Compact Optical Module of Homodyne Detection

  Hideharu Mikami, Takahiro Kurokawa, Koichi Watanabe

  JAPANESE JOURNAL OF APPLIED PHYSICS 51 8 2012年08月 [査読有り][通常論文]
   

  Homodyne detection is a detection technique that significantly amplifies optical signals. It is useful for the readout of multilayer optical discs, where the signal level is quite low. The improvement of optical disc readout signal quality by homodyne detection has been demonstrated experimentally. However, homodyne detection requires a complicated optical system, which causes large-scale implementation and high cost, which prevents practical use of the technique in optical disc systems. In this report, we demonstrated compact implementation of homodyne detection. We proposed and assembled two types of optical module for homodyne detection. The sizes of the modules were 10 x 30 and 10 x 40 mm(2), which were comparable to that of the current optical pickup. Jitter of the attenuated Blu-ray Disc (TM) recordable (BD-R) readout signals was improved from 15 to 7.8% by applying one of the modules. (C) 2012 The Japan Society of Applied Physics
• Read Data Transfer Rate Estimation in Optical Phase Multilevel Recording

  Atsushi Kikukawa, Hideharu Mikami, Tatsuro Ide, Kentaro Osawa, Koichi Watanabe

  JAPANESE JOURNAL OF APPLIED PHYSICS 51 8 2012年08月 [査読有り][通常論文]
   

  The feasibility of increasing the read data transfer rate (DTR) by introducing optical phase multilevel recording technology was investigated using computer simulations. The signals read back from phase marks suffer from strong intersymbol interference (ISI) when the phase marks are recorded with a linear symbol density comparable to that of current optical disc systems; thus, the partial response most-likely (PRML) method is essential. The increase in the decoder size is a serious problem when applying the PRML method to multilevel signal decoding; however, it was shown that this can be resolved by applying run-length limited (RLL) modulations. With these, it was shown that it is possible to decode 4-ary phase-modulated signals with satisfactory performance using PRML. Therefore, we conclude that it is possible to at least double the read DTR by introducing the optical phase multilevel recording technology. (C) 2012 The Japan Society of Applied Physics
• Experimental Demonstration of Optical Phase Multilevel Recording in Microhologram

  Hideharu Mikami, Kentaro Osawa, Eriko Tatsu, Koichi Watanabe

  JAPANESE JOURNAL OF APPLIED PHYSICS 51 8 2012年08月 [査読有り][通常論文]
   

  The microhologram is one of the most promising candidates for the next generation optical disc. It can achieve a huge data capacity because it is suitable for multilayer recording. However, it cannot increase the data transfer rate because of its comparable areal recording density with conventional optical discs. Moreover, the signal level in the readout process of this scheme is in general very low, which prevents its practical use. Recently, an optical phase multilevel scheme that overcomes the above drawbacks of the microhologram has been proposed. The scheme uses an optical phase as stored information, which enables data readout with an extremely high signal-to-noise ratio and multilevel modulation. In this report, recording and readout processes of the proposed scheme are demonstrated experimentally. Four-level phase modulation was successfully regenerated from weak 30 nW microholograms with errors of +7.0/-12.2 degrees, suggesting that a further increase in the number of levels is possible. (C) 2012 The Japan Society of Applied Physics
• Reduction of Interlayer Crosstalk of Multilayer Optical Disc by Using Phase-Diversity Homodyne Detection

  Tatsuro Ide, Kentaro Osawa, Hideharu Mikami, Koichi Watanabe

  JAPANESE JOURNAL OF APPLIED PHYSICS 51 8 2012年08月 [査読有り][通常論文]
   

  We theoretically and experimentally studied the effects of phase-diversity homodyne detection on the interlayer crosstalk of a multilayer optical disc by comparison with those of conventional intensity detection. From analytical studies, we clarified the differences in interlayer crosstalk of both detections. Interlayer crosstalk consists of two noises, the intensity of the stray light N-1 and the interference between the signal and stray light N-2. The noise N-1, which is dominant between these two, drastically decreases with layer spacing in phase-diversity homodyne detection owing to mismatch in the phase distribution between reference and stray light compared with that in intensity detection. Simulations and experiments on a dual-layer Blu-ray Disc (TM) having a layer spacing less than 10 mu m demonstrated that phase-diversity homodyne detection provided higher tolerance to interlayer crosstalk than the conventional intensity detection. (C) 2012 The Japan Society of Applied Physics
• Analysis of Phase Multilevel Recording on Microholograms

  Tatsuro Ide, Hideharu Mikami, Kentaro Osawa, Koichi Watanabe

  JAPANESE JOURNAL OF APPLIED PHYSICS 50 9 2011年09月 [査読有り][通常論文]
   

  An optical phase multilevel recording technique using a microholographic system and phase-diversity homodyne detection for enhancement of optical disc capacity is investigated. In this technique, multilevel phase signals are stored as the fringe shifts along the optical axis and recovered from the arctangent of two homodyne-detected signals. For comparison, phase signals from Blu-ray Disc read-only memory (BD-ROM) and Blu-ray Disc recordable (BD-R) media obtained by phase-diversity homodyne detection are experimentally evaluated. From the experimental results, we demonstrated that phase-diversity homodyne detection is useful for detecting the phase signal modulation of the signal beam from an optical disc. Furthermore, simulation results on microholograms indicate that phase signals from the microholograms are much more stable despite the variety of their sizes than those from BD-ROM. These results demonstrate the potential of this multilevel recording method. (C) 2011 The Japan Society of Applied Physics
• Homodyne detection for readout signals of optical disc with a high-coherence laser

  Kentaro Osawa, Hideharu Mikami, Takahiro Kurokawa, Koichi Watanabe

  OPTICAL DATA STORAGE 2010 7730 2010年 [査読有り][通常論文]
   

  A system using homodyne detection to read out signals from optical discs was simplified by using a high-coherence laser light source. The quality of the readout signal with the simplified system was substantially greater than with conventional detection.
• Optical phase multi-level recording in microhologram

  Hideharu Mikami, Kentaro Osawa, Koichi Watanabe

  OPTICAL DATA STORAGE 2010 7730 2010年 [査読有り][通常論文]
   

  A novel multi-level scheme using optical phase is proposed. It overcomes drawbacks in conventional multi-level schemes and greatly enhances capacity and transfer rate of microholographic optical discs. We demonstrate its feature of high signal-to-noise ratio.
• Amplification of Optical Disk Readout Signals by Homodyne Detection

  Hideharu Mikami, Takeshi Shimano, Takahiro Kurokawa, Tatsuro Ide, Jiro Hashizume, Koichi Watanabe, Harukazu Miyamoto

  JAPANESE JOURNAL OF APPLIED PHYSICS 48 3 2009年03月 [査読有り][通常論文]
   

  We experimentally demonstrated the amplification of optical disk readout signals by homodyne detection. This technique uses optical interference to amplify the signals. We further applied phase-diversity detection to reliably obtain the amplified readout signal. The optical system was carefully designed so that a sufficiently amplified readout signal can be obtained. In particular, we applied a corner cube prism as a reflection mirror to achieve sufficient stability of the interferometric optical system. We experimentally demonstrated a 3.6 times amplification of a Blu-ray Disc readout signal. The estimated signal-to-noise ratio (SNR) improvement for an assumed eight-layer optical disk readout signals by applying homodyne detection on the basis of the observed amplification was +7.9dB, which significantly enables reliable readout of recorded signals. The present technique will be essential for the real commercialization of next-generation multilayer optical disk because of its outstanding ability of SNR improvement. (C) 2009 The Japan Society of Applied Physics
• Signal-Readout System for Optical Pickup with Homodyne Detection Scheme

  Takahiro Kurokawa, Hideharu Mikami, Hiroyuki Minemura, Tatsuro Ide, Koichi Watanabe, Harukazu Miyamoto

  JAPANESE JOURNAL OF APPLIED PHYSICS 48 3 2009年03月 [査読有り][通常論文]
   

  We developed a signal-readout system suitable for optical pickups with a homodyne detection scheme, which is used to amplify signal lights using optical interference. The system consists of an optical-signal detection circuit and a readout-signal generator. The optical-signal detection circuit, which contains pairs of photodiodes connected in series, successfully cancels out large DC components arising from a reference light. This made it possible to avoid the output signal saturation of current-to-voltage amplifiers and raise the upper limit of signal gain. The readout-signal generator generates a readout signal on the basis of the phase-diversity method, which stabilizes readout signal amplitude. By using this system, a signal gain of 3.6 was obtained on a commercially available disc. (C) 2009 The Japan Society of Applied Physics
• Demonstration of Readout-Signal Quality Improvement by Homodyne Detection

  Hideharu Mikami, Takahiro Kurokawa, Koichi Watanabe, Harukazu Miyamoto

  2009 OPTICAL DATA STORAGE TOPICAL MEETING 46 - 48 2009年 [査読有り][通常論文]
  
• Remote preparation of qutrit states with biphotons

  Hideharu Mikami, Takayoshi Kobayashi

  Physical Review A - Atomic, Molecular, and Optical Physics 75 2 2007年02月22日 [査読有り][通常論文]
   

  We report an experimental demonstration of remote preparation of an arbitrary pure qutrit state. A qutrit is encoded in a two-photon (biphoton) polarization state. Prepared states are characterized by quantum state tomography. Experimental imperfection is discussed and evaluated by an experimentally obtained density matrix. The present scheme can develop into generation of an arbitrary two-photon triplet state and accordingly to an essential multiparty quantum communication protocol. Generalization to higher order which enables remote preparation of an arbitrary qudit state and several typical multiphoton entangled states is also shown. © 2007 The American Physical Society.
• Remote preparation of qutrit states with biphotons

  Hideharu Mikami, Takayoshi Kobayashi

  PHYSICAL REVIEW A 75 2 2007年02月 [査読有り][通常論文]
   

  We report an experimental demonstration of remote preparation of an arbitrary pure qutrit state. A qutrit is encoded in a two-photon (biphoton) polarization state. Prepared states are characterized by quantum state tomography. Experimental imperfection is discussed and evaluated by an experimentally obtained density matrix. The present scheme can develop into generation of an arbitrary two-photon triplet state and accordingly to an essential multiparty quantum communication protocol. Generalization to higher order which enables remote preparation of an arbitrary qudit state and several typical multiphoton entangled states is also shown.
• Single-mode approximation of parametric down-conversion

  YM Li, H Mikami, HB Wang, T Kobayashi

  PHYSICAL REVIEW A 72 6 2005年12月 [査読有り][通常論文]
   

  In this paper, we study the theory of spontaneous parametric down-conversion pumped by a short coherent pulse. It is shown that when single spatial mode filters and narrow band optical filters are used to filter the output state of parametric down-conversion, the postselected state of parametric down-conversion can be approximately described by a simple single-mode theory.
• New high-efficiency source of a three-photon W state and its full characterization using quantum state tomography

  H Mikami, YM Li, K Fukuoka, T Kobayashi

  PHYSICAL REVIEW LETTERS 95 15 150404  2005年10月 [査読有り][通常論文]
   

  We propose and demonstrate a new scheme of high-efficiency generation of the three-photon polarization-entangled W state, which is a typical three-qubit entangled state. The high efficiency has enabled the first full characterization of the state by quantum state tomography. We have analyzed the obtained state and observed its nature of tripartite entanglement and robustness of entanglement.
• New high-efficiency source of a three-photon W state and its full characterization using quantum state tomography

  Hideharu Mikami, Yongmin Li, Kyosuke Fukuoka, Takayoshi Kobayashi

  IQEC, International Quantum Electronics Conference Proceedings 2005 1012 - 1013 2005年 [査読有り][通常論文]
   

  We propose and demonstrate a new scheme of high-efficiency generation of the three-photon polarization-entangled W state, which is a typical three-qubit entangled state. The obtained state is characterized using quantum state tomography.
• Generation of the four-photon W state and other multiphoton entangled states using parametric down-conversion

  Hideharu Mikami, Yongmin Li, Takayoshi Kobayashi

  Physical Review A - Atomic, Molecular, and Optical Physics 70 5 A 1 - 52308 2004年11月 [査読有り][通常論文]
   

  Two methods of generating the four-photon W state were proposed. The methods utilized parametric down-conversion processes, linear optical elements, and commercial photon detectors, which are feasible under current technology. The methods could be used to generate the three-photon W state, the three-photon Greenberger-Horne-Zeilinger state, and the three photon maximally entangled photon number state by simply changing some experimental components or the parameters. It was shown that the methods could be developed into methods that generate a general n-photon W state.
• Generation of the four-photon W state and other multiphoton entangled states using parametric down-conversion

  H Mikami, YM Li, T Kobayashi

  PHYSICAL REVIEW A 70 5 2004年11月 [査読有り][通常論文]
   

  We propose two interesting methods of generating the four-photon W state. These methods use parametric down-conversion processes, linear optical elements, and commercial photon detectors, which are readily feasible under current technology. They can also be used to generate the three-photon W state, the three-photon Greenberger-Horne-Zeilinger state, and the three-photon maximally entangled photon-number state (a typical photon-number entanglement state) by simply changing some experimental components or their parameters. Moreover, assuming we have photon number-resolving detectors, these methods can develop into methods that generate a general n-photon W state. They are expected to become powerful tools for experimental investigations of multipartite entanglement and its applications to quantum information processing.

その他活動・業績

• 超高速イメージングで生命科学 (特集 バイオイメージング最前線)

  三上 秀治, 雷 诚, 鈴木 祐太, 小関 泰之, 合田 圭介 O plus E : Optics + electronics 38 (10) 922 -926 2016年10月

特許

• 特開2018-112611:レーザ顕微鏡装置およびフローサイトメーター  2018年07月19日

  合田 圭介, 三上 秀治  国立大学法人 東京大学  201803003401025302
• 特許第6279081号:光学分析装置  2018年01月26日

  三上 秀治  株式会社日立製作所  201803002393453913
• 特許第6266851号:イメージング装置及びイメージング方法  2018年01月05日

  三上 秀治, 合田 圭介  国立研究開発法人科学技術振興機構  201803007586523783
• 特許第6232525号:照射装置、レーザ顕微鏡システム、照射方法及びレーザ顕微鏡の検出方法  2017年10月27日

  三上 秀治, 合田 圭介  国立研究開発法人科学技術振興機構  201803017163687734
• WO2016-147253:テラヘルツ波測定装置  2016年09月22日

  白水 信弘, 三上 秀治, 渡辺 康一  株式会社日立ハイテクノロジーズ  201703004753867256
• 特許第5996665号:CARS顕微鏡  2016年09月02日

  三上 秀治  株式会社日立製作所  201603018331268647
• WO2016-063322:光学分析装置及び生体分子解析装置  2016年04月28日

  三上 秀治  株式会社日立製作所  201703017617176163
• 特許第5923003号:光受信器  2016年04月22日

  家村 光貴, 坂 卓磨, 三上 秀治, 大澤 賢太郎  日本オクラロ株式会社  201603021197459229
• 特許第5796934号:偏波ダイバーシティ光学系装置、復調器及び送受信機  2015年08月28日

  大澤 賢太郎, 三上 秀治  日本オクラロ株式会社  201503012590475590
• 特許第5780932号:光情報記録再生装置、光情報記録装置  2015年07月24日

  三上 秀治  日立コンシューマエレクトロニクス株式会社  201503004046477315
• 特許第5778624号:光情報再生装置及び光情報再生方法  2015年07月17日

  三上 秀治  日立コンシューマエレクトロニクス株式会社  201503011653075761
• 特許第5737874号:復調器及び光送受信機  2015年05月01日

  三上 秀治  日本オクラロ株式会社  201503035570941721
• 特許第5709543号:干渉計、復調器および送受信器  2015年03月13日

  大澤 賢太郎, 三上 秀治  日本オクラロ株式会社  201503087986528823
• 特許第5668110号:光学素子および光学装置  2014年12月19日

  峯邑 浩行, 安齋 由美子, 三上 秀治  株式会社日立製作所  201503063437336630
• 特許第5530205号:干渉計、復調器及び光通信モジュール  2014年04月25日

  三上 秀治, 小暮 太一  日本オクラロ株式会社  201403082901022811
• 特許第5525657号:光情報記録再生装置  2014年04月18日

  三上 秀治, 渡辺 康一  日立コンシューマエレクトロニクス株式会社  201503077887004981
• 特許第5468033号:光情報再生装置及び光情報記録再生装置  2014年02月07日

  三上 秀治  日立コンシューマエレクトロニクス株式会社  201403024239154850
• 特許第5452040号:光学的情報再生方法、光ヘッドおよび光ディスク装置  2014年01月10日

  三上 秀治, 黒川 貴弘  日立コンシューマエレクトロニクス株式会社  201403067162406720
• 特許第5409479号:光情報再生装置、光情報記録装置及び情報記録方法  2013年11月15日

  三上 秀治  日立コンシューマエレクトロニクス株式会社  201403055781875648
• 特開2013-182653:光情報再生装置、光情報記録装置及び光情報記録方法  2013年09月12日

  三上 秀治  日立コンシューマエレクトロニクス株式会社  201303020184142987
• 特許第5309008号:光情報記録再生装置および光情報再生装置  2013年07月05日

  三上 秀治, 宮本 治一  日立コンシューマエレクトロニクス株式会社  201303068756097468
• 特許第5256161号:光情報記録再生装置及び情報再生装置  2013年04月26日

  三上 秀治, 渡辺 康一, 宮本 治一  日立コンシューマエレクトロニクス株式会社  201303070586216445
• 特許第5153424号:光ヘッド及び光ディスク装置  2012年12月14日

  三上 秀治, 宮本 治一, 黒川 貴弘  株式会社日立製作所  201303093257161460
• 特許第5043049号:光学的情報再生方法及び光ディスク装置  2012年07月20日

  三上 秀治, 宮本 治一, 黒川 貴弘  株式会社日立製作所  201303015005606085
• 特許第4972602号:光信号検出回路及びそれを用いた情報再生装置  2012年04月13日

  黒川 貴弘, 三上 秀治  株式会社日立製作所  201303032753065277
• 特許第4861948号:光ヘッドおよび光ディスク装置  2011年11月11日

  三上 秀治  日立コンシューマエレクトロニクス株式会社  201203089942400626
• 特許第4564948号:光情報検出方法、光ヘッド及び光ディスク装置  2010年08月06日

  宮本 治一, 三上 秀治, 島野 健  株式会社日立製作所  201103070562874102
• 特開2008-243273:光ヘッド及び光情報記録媒体の再生方法  2008年10月09日

  橋爪 滋郎, 三上 秀治, 島野 健  株式会社日立製作所  200903041968313740

共同研究・競争的資金等の研究課題

• 先端バイオイメージング支援プラットフォーム

  日本学術振興会：科学研究費助成事業

  研究期間 : 2022年04月 -2028年03月 

  代表者 : 鍋倉 淳一, 根本 知己, 山中 めぐみ, 上野 直人, 真野 昌二, 大浪 修一, 藤森 俊彦, 野中 茂紀, 今村 健志, 平岡 泰, 甲本 真也, 松田 道行, 洲崎 悦生, 稲葉 一男, 菅谷 佑樹, 澤田 和明, 佐藤 良勝, 三上 秀治, 岡田 康志, 大野 伸彦, 安永 卓生, 太田 啓介, 小池 正人, 宮澤 淳夫, 深澤 有吾, 渡辺 雅彦, 豊岡 公徳, 片岡 洋祐, 定藤 規弘, 青木 茂樹, 岡田 直大, 林 拓也, 内田 誠一, 桧垣 匠, 舟橋 啓, 小田 祥久, 木森 義隆

   

  前年度までの新学術領域研究（学術研究支援基盤形成）「先端バイオイメージング支援プラットフォーム（ABiS）」の実績を元に、研究者のニーズを調査し、新たな支援内容も加えた体制を構築し、光学顕微鏡、電子顕微鏡、磁気共鳴機器による画像取得、およびそれらの機器より得られた画像の解析の支援を行った。2022年度は、光学顕微鏡支援として101件、電子顕微鏡支援として45件、磁気共鳴画像支援として17件、画像解析支援として17件行い、トレーニングを14回開催した。 新たな支援活動を行うにあたり、オフィシャルサイトをリニューアルした。新しいオフィシャルサイトでは、各支援内容を紹介する動画の掲載や連携している国際バイオイメージングコンソーシアム（GBI: Global BioImaging）の情報の自動アップデート機能などを実装した。公募の周知活動として、このオフィシャルサイトを随時更新して最新情報を発信するとともに、公募案内のポスターをリニューアルして、大学・研究機関に送付した（1,353部）。また、新しい体制を紹介するためのリーフレットも刷新し、周知活動に用いた。 本年度は、発生生物学会第55回大会、第74回日本細胞生物学会年会、日本植物学会第86回大会、第81回日本癌学会学術総会、第95回日本生化学会大会、第45回日本分子生物学会年会、日本生理学会第100回記念大会、日本薬学会143年会において、ブース出展やランチョンセミナー、シンポジウム共催を行い、大会参加者へ支援概要や応募方法の説明を行った。上記の大会のうち、第81回日本癌学会学術総会、第95回日本生化学会大会、第45回日本分子生物学会年会、日本生理学会第100回記念大会、日本薬学会143年会は、生命科学連携推進協議会のもと、4つのプラットフォームが合同で参加した。
• 高速・高次元閉ループ光計測技術の確立と神経科学への応用

  科学技術振興機構：戦略的な研究開発の推進 戦略的創造研究推進事業 CREST

  研究期間 : 2022年 -2027年 

  代表者 : 三上 秀治

   

  従来の大規模計測・解析の限界を打破する新しい新たな実験手法「高速・高次元閉ループ光計測技術」を確立し、次世代のバイオDXに貢献する。先端光学技術およびAI技術を軸とした技術開発を行い、開発した装置をマウスおよび線虫の神経系の研究に適用して従来の実験のアプローチでは現実的な時間内での解析が困難であった神経系の機序解明を目指す。
• ニューロンレベル脳・人工脳インターフェース

  日本学術振興会：科学研究費助成事業

  研究期間 : 2022年06月 -2024年03月 

  代表者 : 三上 秀治

   

  本年度は予備的検討として線虫の頭部ニューロン群の高速3D撮像を行い、取得データに対してオフラインで細胞位置の解析を試みるとともに、光操作のための高速光変調の検討を行った。まず、独自開発した高速ライトシート顕微鏡を用いて線虫の頭部神経の撮像を行うため、明視野画像をもとに線虫頭部を視野中心に固定するトラッキングステージを製作し、高速撮像(毎秒50ボリューム)に耐える追従動作を確認した。次に、高速ライトシート顕微鏡の撮像条件を線虫頭部神経にあわせて調整し、自由行動中の線虫の撮像に十分な速度である毎秒50ボリュームの撮像を行った。取得データを各種画像解析ソフトウエアにより解析し、頭部全ニューロンの8割弱にあたる約150個の神経細胞の検出および追跡が可能であることを確認した。また、リアルタイムに特定のニューロン群を選択的に光操作するための光学システムとして、高速な空間光変調器および多光子励起が可能なフェムト秒パルスレーザーを導入し、特定のニューロンにレーザー光を集光・照射する動作の時定数を詳細に検証した。なお、検証のため、照射対象はCMOSカメラで明視野撮像した蛍光ビーズとした。検証の結果、カメラの撮像から集光までの所要時間は90 ms程度であり、自由行動中の線虫であってもリアルタイムに追従しながら集光・照射できる見込みを得た。加えて、一連の処理の各要素に要した時間も確認しており、特に計算処理に要する部分が支配的であることが確認された。この点については、計算アルゴリズムの高速化および計算ハードウエアの変更による大幅な高速化が見込まれており、現状の2D撮像から3D撮像に拡張する場合においてもリアルタイム動作を実現する見通しを得た。
• 情報通信技術を応用した光学的大規模膜電位計測法の開拓

  日本学術振興会：科学研究費助成事業

  研究期間 : 2021年04月 -2024年03月 

  代表者 : 三上 秀治

   

  本年度は生体試料の計測のための環境構築を行うとともに、多重検出方式の検討を前年度に引き続き行った。生体試料計測としてマウス脳皮質の計測を想定し、マウスの飼育環境や手術から観察までの一連の作業に要する機材の整備を行い、in vivoでの神経活動計測が可能な環境を整備した。加えて、方式検討の基盤となる多光子顕微鏡もマウス観察向けに新規に設計、構築を行い、前年度に構築した装置とあわせて、様々な生体試料を用いた評価基盤が構築できた。多重化方式としては主として時分割多重方式の検討を行い、前年度に検討した周波数分割多重との比較を試みた。基礎的な検討として時分割多重は前年度に用いたものと同じ高速な空間光変調器による集光パターンの逐次的な切り替えにより実装した。このため、時定数の評価に必要な装置の特性は前年度に評価済みのものを用いた。動作確認としては３つの直径10 μmの蛍光ビーズを用い、周波数分割多重の実験と同様に明視野画像の画像処理により特定した各ビーズの座標に逐次的にパルスレーザーを照射し、取得した信号波形から各蛍光の強度を計測することができた。本検討では時分割多重方式のみの実装のため逐次的な検出（ランダムアクセス顕微鏡と呼ばれるものに相当）を行ったことになるが、実際は周波数分割多重等の他方式との組み合わせが可能である。このことを見越して各ビーズあたり１点の測定ではなく、周辺の複数点の測定により蛍光ビーズの座標を検出する動作も併せて試み、１秒あたり1 μmのステップで移動させた蛍光ビーズを（明視野画像の情報を用いることなく）追跡することができた。このような動作は計測対象が移動する場合に有効であり、特に通常の撮像に長時間を要する３次元計測において有効であると見込まれる。
• 生命活動をリアルタイムに追跡する超高速3D蛍光顕微鏡

  科学技術振興機構：戦略的な研究開発の推進 戦略的創造研究推進事業 さきがけ

  研究期間 : 2017年 -2021年 

  代表者 : 三上 秀治

   

  従来よりも数10倍高速な、1,000ボリューム/秒の超高速3D蛍光顕微鏡技術を開発する。これにより、活動する生物をリアルタイムかつ正確に記録し、神経活動をはじめとする様々な生命活動の組織・細胞レベルでの理解に貢献する。

教育活動情報

主要な担当授業